The two temporal limits of Itzurun in Zumaia receive the official designation of stratotype

2010/05/06 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Geologia

Last year two international organizations, the International Committee on Stratigraphy ICS and the International Union of Geological Sciences (IUGS), called the stratotype the two time limits that stand out on the cliffs of Itzurun in Zumaia. Today, in an official act, both limits will be marked with golden nails.

Specifically, Daniense/Selandiarra and Selandiarra/Thanetiense are the temporary limits that are to be called stratotype. Both belong to the Paleocene. The first, D/S, dates from 61.1 million years ago; the most remarkable geological fact of the time is the spectacular descent of sea level. The second (S/T), for its part, was 58.7 million years ago and is important for the investment of the poles.

However, these are not the only limits that can be studied on the cliffs of Zumaia, as others also appear very clean. One of them is the transition from the Cretaceous to the Tertiary (limit K/T). It is well known for being related to the disappearance of dinosaurs. Although he is not as well known as himself, it should also be noted that of Paleocene to Eocene (limit P/E). In fact, at that time, there was one of the greatest climatic heats in Earth's history.

Today's event will be attended by Stanley Finney, Eustoquio Molina and Birger Schmitz, members of the ICS committee, and Xabier Orue-Etxebarria, professor of Paleontology at the UPV.